configure.ac: Provide a non-empty default manpage extension.

This has been a bug forever, but there's been a corresponding bug
in the `mdw_MANEXT' macro forever which ignores the supplied default
and uses `mLib' instead, so nobody noticed.  Until I fixed the
other bug and my build broke.

diff --git a/configure.ac b/configure.ac
index ab8d2a8..60f82b9 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -42,7 +42,7 @@ mdw_LIBTOOL_VERSION_INFO
 
 AC_CHECK_PROGS([AUTOM4TE], [autom4te])
 
-mdw_MANEXT
+mdw_MANEXT([mLib])
 
 AC_DEFINE_UNQUOTED([SRCDIR], ["$(cd $srcdir && pwd)"],
                   [absolute pathname for the source directory.])